1. Field of the Invention
The present invention relates to novel recognition method and apparatus, and more specifically to method and apparatus for recognizing patterns such as figures, letters, etc. on the basis of a novel judgment operation.
2. Description of Related Art
Heretofore, mechanical or electrical recognition apparatuses have been constructed such that its judgment is made on the basis of coincidence in numerical values of physical amounts such as lengths, electric currents, electric voltages, etc., or in accordance with the large-and-small relation in those numerical values. For example, computers are founded on a binary notation, which can be realized by ON and OFF of electric currents. Because of this fundamental restriction, the computers cannot carry out an operation similar to a thinking process, particularly judgment process of a human being. In addition, the computers cannot execute the pattern recognition, unless patterns that essentially is of an analog amount are converted into a digital amount.
Here, turning to the recognition of a human being, it is based on judgment for identity: A=A (or A') where A and A' are representative of conceptions. Therefore, this judgment for identity is not the same as that can be obtained from simple comparison of physical values as in the conventional mechanical and electrical recognition apparatuses. In the thinking process of a human being, for example, dogs, horses and cattle are judged to be the same in the category "mammalia", and men and women are the same in the category "humankind". Namely, the recognition of a human being can can be said to be categorization of objects to be recognized. Specifically, the decision of identity is performed at various levels of categories, so that an object to be recognized can be identified in the system of known conceptions. At the same time, a property inherent to an object itself to be recognized can be known.
On the other hand, the conventional mechanical and electrical recognition apparatus cannot perform the above mentioned conception identity judgment. Briefly, in the conventional pattern recognition, a plurality of characters are extracted from a given pattern such as a letter and a figure by means of complicated procedures, and then compared with a group of characters extracted from reference patterns previously prepared, so that the distances between the given pattern and the reference patterns are calculated. Namely, only a simple measurement of one absolute amount is carried out.
In addition, in the conventional pattern recognition, even if a given pattern should be deemed to be the same as one reference pattern, if the given pattern is different in position, angular direction or scale from the reference pattern, the given pattern is often judged to be different from the reference pattern. In other words, a proper recognition is greatly restricted by the position, the angular direction and the scale. In this connection, as one means enabling a proper recognition irrespectively of variation in the position and the angular direction, it is considered to parallel-shift or rotate the given pattern. However, a processing for such a shift or rotation will require a large amount of computations because the characters of the given pattern is derived by means of digital computation.